helper-functions.php

<?php

/**
 *
 */

/**
 * Helper functions for the plugin
 */
if (!defined('ABSPATH')) {
    exit; // Exit if accessed directly
}

/**
 * Send a single email (no trigger required)
 *
 * @param WP_Post $email_post   Email post object
 * @param WP_User $user         User object
 * @param array   $placeholders Any placeholders that need to be replaced
 */
function pce_send_email($email_post, $user, $placeholders = array())
{
    $to      = $user->user_email;
    $subject = pce_process_placeholders(get_the_title($email_post), $user, $placeholders);
    $body    = pce_process_placeholders(get_the_content(null, false, $email_post), $user, $placeholders);
    $headers = array('Content-Type: text/html; charset=UTF-8');
    return wp_mail($to, $subject, $body, $headers);
}

/**
 * Send emails for certain trigger
 *
 * @param int/string  $trigger      Trigger (tag) ID/slug
 * @param int/WP_User $user         User ID or User Object
 * @param array       $placeholders Any placeholders that need to be replaced
 */
function pce_send_emails($trigger = '', $user = 0, $placeholders = array())
{
    if (!term_exists($trigger, 'trigger')) {
        return new WP_Error('pie-custom-emails', 'No trigger found with ID/slug: ' . $trigger);
    }
    if (!is_a($user, 'WP_User')) {
        $user = get_user_by('id', $user);
    }
    if (!$user) {
        return new WP_Error('pie-custom-emails', 'No user found');
    }
    // Get an array of all emails with set trigger
    $emails = pce_get_emails($trigger);
    if (empty($emails)) {
        return new WP_Error('pie-custom-emails', 'No emails found for trigger: ' . $trigger);
    }
    // loop through emails (post objects) and send
    foreach ($emails as $email_post) {
        pce_send_email($email_post, $user, $placeholders);
    }
}

/**
 * Retrieve email posts by trigger (tag)
 *
 * @param int/string $trigger Trigger (tag) ID/slug
 */
function pce_get_emails($trigger = '')
{
    $field = is_int($trigger) ? 'term_id' : 'slug';
    $args  = array(
        'posts_per_page' => -1,
        'post_type'      => 'pie_email',
        'tax_query'      => array(
            array(
                'taxonomy' => 'trigger',
                'field'    => $field,
                'terms'    => $trigger,
            )
        )
    );
    return get_posts($args);
}

/**
 * Parse content to replace placeholders with User info
 *
 * @param string  $content      Email content
 * @param WP_User $user         User object
 * @param array   $placeholders Any placeholders that need to be replaced
 */
function pce_process_placeholders($content, $user, $placeholders = array())
{
    $first_name = get_user_meta($user->ID, 'first_name', true) ? get_user_meta($user->ID, 'first_name', true) : '{{user.first_name}}';
    $last_name  = get_user_meta($user->ID, 'last_name', true) ? get_user_meta($user->ID, 'last_name', true) : '{{user.last_name}}';
    $defaults   = array(
        '{{user.first_name}}' => $first_name,
        '{{user.last_name}}'  => $last_name,
        '{{user.email}}'      => $user->user_email,
    );
    $to_replace = wp_parse_args($placeholders, $defaults);
    return str_replace(array_keys($to_replace), array_values($to_replace), $content);
}

/**
 * Filter ACF date in format(Ymd) to F j, Y
 */
function pce_filter_acf_date($date)
{
    if ($new_date = DateTime::createFromFormat('Ymd', $date)) {
        return $new_date;
    }
    return $date;
}
add_filter('pce_filter_acf_date', 'pce_filter_acf_date');